gstreamer/gst/gstplugin.h
2011-06-09 17:54:27 +01:00

411 lines
15 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstplugin.h: Header for plugin subsystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifndef __GST_PLUGIN_H__
#define __GST_PLUGIN_H__
#include <gst/gstconfig.h>
#include <time.h> /* time_t */
#include <sys/types.h> /* off_t */
#include <sys/stat.h> /* off_t */
#include <gmodule.h>
#include <gst/gstobject.h>
#include <gst/gstmacros.h>
#include <gst/gststructure.h>
G_BEGIN_DECLS
typedef struct _GstPlugin GstPlugin;
typedef struct _GstPluginClass GstPluginClass;
typedef struct _GstPluginPrivate GstPluginPrivate;
typedef struct _GstPluginDesc GstPluginDesc;
/**
* gst_plugin_error_quark:
*
* Get the error quark.
*
* Returns: The error quark used in GError messages
*/
GQuark gst_plugin_error_quark (void);
/**
* GST_PLUGIN_ERROR:
*
* The error message category quark
*/
#define GST_PLUGIN_ERROR gst_plugin_error_quark ()
/**
* GstPluginError:
* @GST_PLUGIN_ERROR_MODULE: The plugin could not be loaded
* @GST_PLUGIN_ERROR_DEPENDENCIES: The plugin has unresolved dependencies
* @GST_PLUGIN_ERROR_NAME_MISMATCH: The plugin has already be loaded from a different file
*
* The plugin loading errors
*/
typedef enum
{
GST_PLUGIN_ERROR_MODULE,
GST_PLUGIN_ERROR_DEPENDENCIES,
GST_PLUGIN_ERROR_NAME_MISMATCH
} GstPluginError;
/**
* GstPluginFlags:
* @GST_PLUGIN_FLAG_CACHED: Temporarily loaded plugins
* @GST_PLUGIN_FLAG_BLACKLISTED: The plugin won't be scanned (again)
*
* The plugin loading state
*/
typedef enum
{
GST_PLUGIN_FLAG_CACHED = (1<<0),
GST_PLUGIN_FLAG_BLACKLISTED = (1<<1)
} GstPluginFlags;
/**
* GstPluginDependencyFlags:
* @GST_PLUGIN_DEPENDENCY_FLAG_NONE : no special flags
* @GST_PLUGIN_DEPENDENCY_FLAG_RECURSE : recurse into subdirectories
* @GST_PLUGIN_DEPENDENCY_FLAG_PATHS_ARE_DEFAULT_ONLY : use paths
* argument only if none of the environment variables is set
* @GST_PLUGIN_DEPENDENCY_FLAG_FILE_NAME_IS_SUFFIX : interpret
* filename argument as filter suffix and check all matching files in
* the directory
*
* Flags used in connection with gst_plugin_add_dependency().
*
* Since: 0.10.22
*/
typedef enum {
GST_PLUGIN_DEPENDENCY_FLAG_NONE = 0,
GST_PLUGIN_DEPENDENCY_FLAG_RECURSE = (1 << 0),
GST_PLUGIN_DEPENDENCY_FLAG_PATHS_ARE_DEFAULT_ONLY = (1 << 1),
GST_PLUGIN_DEPENDENCY_FLAG_FILE_NAME_IS_SUFFIX = (1 << 2)
} GstPluginDependencyFlags;
/**
* GstPluginInitFunc:
* @plugin: The plugin object
*
* A plugin should provide a pointer to a function of this type in the
* plugin_desc struct.
* This function will be called by the loader at startup. One would then
* register each #GstPluginFeature.
*
* Returns: %TRUE if plugin initialised successfully
*/
/* FIXME 0.11: Make return void */
typedef gboolean (*GstPluginInitFunc) (GstPlugin *plugin);
/**
* GstPluginInitFullFunc:
* @plugin: The plugin object
* @user_data: extra data
*
* A plugin should provide a pointer to a function of either #GstPluginInitFunc
* or this type in the plugin_desc struct.
* The function will be called by the loader at startup. One would then
* register each #GstPluginFeature. This version allows
* user data to be passed to init function (useful for bindings).
*
* Returns: %TRUE if plugin initialised successfully
*
* Since: 0.10.24
*
*/
/* FIXME 0.11: Merge with GstPluginInitFunc */
typedef gboolean (*GstPluginInitFullFunc) (GstPlugin *plugin, gpointer user_data);
/**
* GstPluginDesc:
* @major_version: the major version number of core that plugin was compiled for
* @minor_version: the minor version number of core that plugin was compiled for
* @name: a unique name of the plugin
* @description: description of plugin
* @plugin_init: pointer to the init function of this plugin.
* @version: version of the plugin
* @license: effective license of plugin
* @source: source module plugin belongs to
* @package: shipped package plugin belongs to
* @origin: URL to provider of plugin
* @release_datetime: date time string in ISO 8601 format (or rather, a
* subset thereof), or NULL. Allowed are the following formats:
* "YYYY-MM-DD" and "YYY-MM-DDTHH:MMZ" (with 'T' a separator and 'Z'
* indicating UTC/Zulu time). This field should be set via the
* GST_PACKAGE_RELEASE_DATETIME preprocessor macro (Since: 0.10.31)
*
* A plugin should export a variable of this type called plugin_desc. The plugin
* loader will use the data provided there to initialize the plugin.
*
* The @licence parameter must be one of: LGPL, GPL, QPL, GPL/QPL, MPL,
* BSD, MIT/X11, Proprietary, unknown.
*/
struct _GstPluginDesc {
gint major_version;
gint minor_version;
const gchar *name;
const gchar *description;
GstPluginInitFunc plugin_init;
const gchar *version;
const gchar *license;
const gchar *source;
const gchar *package;
const gchar *origin;
const gchar *release_datetime;
/*< private >*/
gpointer _gst_reserved[GST_PADDING - 1];
};
#define GST_TYPE_PLUGIN (gst_plugin_get_type())
#define GST_IS_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_PLUGIN))
#define GST_IS_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_PLUGIN))
#define GST_PLUGIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_PLUGIN, GstPlugin))
#define GST_PLUGIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_PLUGIN, GstPluginClass))
#define GST_PLUGIN_CAST(obj) ((GstPlugin*)(obj))
/**
* GstPlugin:
*
* The plugin object
*/
struct _GstPlugin {
GstObject object;
/*< private >*/
GstPluginDesc desc;
GstPluginDesc *orig_desc;
unsigned int flags;
gchar * filename;
gchar * basename; /* base name (non-dir part) of plugin path */
GModule * module; /* contains the module if plugin is loaded */
off_t file_size;
time_t file_mtime;
gboolean registered; /* TRUE when the registry has seen a filename
* that matches the plugin's basename */
GstPluginPrivate *priv;
gpointer _gst_reserved[GST_PADDING - 1];
};
struct _GstPluginClass {
GstObjectClass object_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
#ifdef GST_PACKAGE_RELEASE_DATETIME
#define __GST_PACKAGE_RELEASE_DATETIME GST_PACKAGE_RELEASE_DATETIME
#else
#define __GST_PACKAGE_RELEASE_DATETIME NULL
#endif
/**
* GST_PLUGIN_DEFINE:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* plugin. One would use this macro to export a plugin, so that it can be used
* by other applications.
*
* The macro uses a define named PACKAGE for the #GstPluginDesc,source field.
* When using autoconf, this is usually set automatically via the AC_INIT
* macro, and set in config.h. If you are not using autoconf, you will need to
* define PACKAGE yourself and set it to a short mnemonic string identifying
* your application/package, e.g. 'someapp' or 'my-plugins-foo.
*
* If defined, the GST_PACKAGE_RELEASE_DATETIME will also be used for the
* #GstPluginDesc,release_datetime field.
*/
#define GST_PLUGIN_DEFINE(major,minor,name,description,init,version,license,package,origin) \
G_BEGIN_DECLS \
GST_PLUGIN_EXPORT GstPluginDesc gst_plugin_desc = { \
major, \
minor, \
name, \
(gchar *) description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
__GST_PACKAGE_RELEASE_DATETIME, \
GST_PADDING_INIT \
}; \
G_END_DECLS
/**
* GST_PLUGIN_DEFINE_STATIC:
* @major: major version number of the gstreamer-core that plugin was compiled for
* @minor: minor version number of the gstreamer-core that plugin was compiled for
* @name: short, but unique name of the plugin
* @description: information about the purpose of the plugin
* @init: function pointer to the plugin_init method with the signature of <code>static gboolean plugin_init (GstPlugin * plugin)</code>.
* @version: full version string (e.g. VERSION from config.h)
* @license: under which licence the package has been released, e.g. GPL, LGPL.
* @package: the package-name (e.g. PACKAGE_NAME from config.h)
* @origin: a description from where the package comes from (e.g. the homepage URL)
*
* This macro needs to be used to define the entry point and meta data of a
* local plugin. One would use this macro to define a local plugin that can only
* be used by the own application.
*
* The macro uses a define named PACKAGE for the #GstPluginDesc.source field.
*
* Deprecated: Use gst_plugin_register_static() instead. This macro was
* deprecated because it uses constructors, which is a compiler feature not
* available on all compilers.
*
*/
/* We don't have deprecation guards here on purpose, it's enough to have
* deprecation guards around _gst_plugin_register_static(), and will result in
* much better error messages when compiling with -DGST_DISABLE_DEPRECATED */
#define GST_PLUGIN_DEFINE_STATIC(major,minor,name,description,init,version,license,package,origin) \
static void GST_GNUC_CONSTRUCTOR \
_gst_plugin_static_init__ ##init (void) \
{ \
static GstPluginDesc plugin_desc_ = { \
major, \
minor, \
name, \
(gchar *) description, \
init, \
version, \
license, \
PACKAGE, \
package, \
origin, \
NULL, \
GST_PADDING_INIT \
}; \
_gst_plugin_register_static (&plugin_desc_); \
}
/**
* GST_LICENSE_UNKNOWN:
*
* To be used in GST_PLUGIN_DEFINE or GST_PLUGIN_DEFINE_STATIC if usure about
* the licence.
*/
#define GST_LICENSE_UNKNOWN "unknown"
/* function for filters */
/**
* GstPluginFilter:
* @plugin: the plugin to check
* @user_data: the user_data that has been passed on e.g. gst_registry_plugin_filter()
*
* A function that can be used with e.g. gst_registry_plugin_filter()
* to get a list of plugins that match certain criteria.
*
* Returns: TRUE for a positive match, FALSE otherwise
*/
typedef gboolean (*GstPluginFilter) (GstPlugin *plugin,
gpointer user_data);
GType gst_plugin_get_type (void);
#ifndef GST_DISABLE_DEPRECATED
void _gst_plugin_register_static (GstPluginDesc *desc);
#endif
gboolean gst_plugin_register_static (gint major_version,
gint minor_version,
const gchar *name,
const gchar *description,
GstPluginInitFunc init_func,
const gchar *version,
const gchar *license,
const gchar *source,
const gchar *package,
const gchar *origin);
gboolean gst_plugin_register_static_full (gint major_version,
gint minor_version,
const gchar *name,
const gchar *description,
GstPluginInitFullFunc init_full_func,
const gchar *version,
const gchar *license,
const gchar *source,
const gchar *package,
const gchar *origin,
gpointer user_data);
const gchar* gst_plugin_get_name (GstPlugin *plugin);
const gchar* gst_plugin_get_description (GstPlugin *plugin);
const gchar* gst_plugin_get_filename (GstPlugin *plugin);
const gchar* gst_plugin_get_version (GstPlugin *plugin);
const gchar* gst_plugin_get_license (GstPlugin *plugin);
const gchar* gst_plugin_get_source (GstPlugin *plugin);
const gchar* gst_plugin_get_package (GstPlugin *plugin);
const gchar* gst_plugin_get_origin (GstPlugin *plugin);
const GstStructure* gst_plugin_get_cache_data (GstPlugin * plugin);
void gst_plugin_set_cache_data (GstPlugin * plugin, GstStructure *cache_data);
GModule * gst_plugin_get_module (GstPlugin *plugin);
gboolean gst_plugin_is_loaded (GstPlugin *plugin);
gboolean gst_plugin_name_filter (GstPlugin *plugin, const gchar *name);
GstPlugin * gst_plugin_load_file (const gchar *filename, GError** error);
GstPlugin * gst_plugin_load (GstPlugin *plugin);
GstPlugin * gst_plugin_load_by_name (const gchar *name);
void gst_plugin_add_dependency (GstPlugin * plugin,
const gchar ** env_vars,
const gchar ** paths,
const gchar ** names,
GstPluginDependencyFlags flags);
void gst_plugin_add_dependency_simple (GstPlugin * plugin,
const gchar * env_vars,
const gchar * paths,
const gchar * names,
GstPluginDependencyFlags flags);
void gst_plugin_list_free (GList *list);
G_END_DECLS
#endif /* __GST_PLUGIN_H__ */